import java.util.Date;
//import java.sql.Date;
import static java.lang.Math.*;

/**
 *
 * Created with IntelliJ IDEA.
 * Description:
 * User: 0
 * Date: 2023-03-17
 * Time: 22:14
 */
    class Student {
        private String name;//普通成员变量
        private int age;

        public static String classRoom = "301";//教室【就只有1份了】 类变量 / 静态成员变量   所有对象共用的

        //这个不带参数的构造方法 如果有其他的构造方法 那么这个就不会被自动生成的
        public Student() {
            //this.name = "gaobo";
            //this.age = 18;
            //this("gaobo",18);
            //会帮你初始化
            System.out.println("不带参数的构造方法");
        }
        public Student(String name, int age) {
            //this("gaobo",18);
            this.name = name;
            this.age = age;
            System.out.println("调用带2个参数的构造方法");
        }

    /*public Student(String name, int age, String classRoom) {
        this.name = name;
        this.age = age;
        this.classRoom = classRoom;
    }*/

        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public int getAge() {
            return age;
        }
        public void setAge(int age) {
            this.age = age;
        }
        public void doClass() {
            //this("fafa",10);
            //this.print();
            System.out.println(this.name+" 上课！");
        }
        public void print() {
            //funcStatic();
            System.out.println("姓名："+this.name+" 年龄："+this.age);

            {
                System.out.println("普通代码块：没有实际的意义，执行这个代码块没有任何的作用！");
            }
        }

        //类方法  不依赖对象
        public static void funcStatic() {
            //print();
        /*Student student1 = new Student("zhangsan",18);
        student1.print();
        */
            System.out.println("funcStatic().........");
        }

    }


    public class Test {

        public static void func1() {

        }


        public static void main(String[] args) {
            //Student.funcStatic();
            func1();



        /*Student student1 = new Student("zhangsan",18);
        Student student2 = student1;*/

      /*  Student student1 = new Student("zhangsan",18);
        student1 = new Student("zhangsan2",18);
        student1 = new Student("zhangsan3",18);*/

       /* Student student1 = null;
        System.out.println(student1.classRoom);//*/
        }


        public static void main6(String[] args) {
            Student student1 = new Student("zhangsan",18);
            Student student2 = new Student("lisi",6);
            Student student3 = new Student("wangwu",28);
        /*System.out.println("教室是："+student1.classRoom);
        System.out.println("教室是："+student2.classRoom);
        System.out.println("教室是："+student3.classRoom);*/

            System.out.println("教室是："+Student.classRoom);
        }





        public static void main5(String[] args) {
            Student student = new Student();
            //student.name = "zhangsan";
            student.setName("zhangsan");
            //student.age = 10;
            student.setAge(10);
            System.out.println(student.getName());

            student.print();
        }
        public static void main4(String[] args) {
            double x = 19.9;
            double y = 90.0;
            //double result = Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
            double result = sqrt(pow(x, 2) + pow(y, 2));
            System.out.println(result);
        }
        public static void main3(String[] args) {
            Date date = new Date();
            int[] array = {1,2,3,4};
            //Arrays.sort(array);

        }
        public static void main2(String[] args) {
            Student student = new Student();
            //student.name = "zhangsan";
            //student.age = 10;
            student.print();

        }



        public static void main1(String[] args) {
            Student student = new Student();
            student.print();

            Student student2 = null;//student2 不指向任何对象


        }

    }

